From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758112AbaKSWVH (ORCPT ); Wed, 19 Nov 2014 17:21:07 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56108 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932568AbaKSUyM (ORCPT ); Wed, 19 Nov 2014 15:54:12 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Herbert Xu , "David S. Miller" Subject: [PATCH 3.17 042/141] tun: Fix csum_start with VLAN acceleration Date: Wed, 19 Nov 2014 12:51:05 -0800 Message-Id: <20141119205152.045115160@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141119205150.700188369@linuxfoundation.org> References: <20141119205150.700188369@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Herbert Xu commit a8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd upstream. When VLAN acceleration is in use on the xmit path, we end up setting csum_start to the wrong place. The result is that the whoever ends up doing the checksum setting will corrupt the packet instead of writing the checksum to the expected location, usually this means writing the checksum with an offset of -4. This patch fixes this by adjusting csum_start when VLAN acceleration is detected. Fixes: 6680ec68eff4 ("tuntap: hardware vlan tx support") Signed-off-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/tun.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1225,6 +1225,10 @@ static ssize_t tun_put_user(struct tun_s struct tun_pi pi = { 0, skb->protocol }; ssize_t total = 0; int vlan_offset = 0, copied; + int vlan_hlen = 0; + + if (vlan_tx_tag_present(skb)) + vlan_hlen = VLAN_HLEN; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) < 0) @@ -1276,7 +1280,8 @@ static ssize_t tun_put_user(struct tun_s if (skb->ip_summed == CHECKSUM_PARTIAL) { gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; - gso.csum_start = skb_checksum_start_offset(skb); + gso.csum_start = skb_checksum_start_offset(skb) + + vlan_hlen; gso.csum_offset = skb->csum_offset; } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; @@ -1289,10 +1294,9 @@ static ssize_t tun_put_user(struct tun_s } copied = total; - total += skb->len; - if (!vlan_tx_tag_present(skb)) { - len = min_t(int, skb->len, len); - } else { + len = min_t(int, skb->len + vlan_hlen, len); + total += skb->len + vlan_hlen; + if (vlan_hlen) { int copy, ret; struct { __be16 h_vlan_proto; @@ -1303,8 +1307,6 @@ static ssize_t tun_put_user(struct tun_s veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); - len = min_t(int, skb->len + VLAN_HLEN, len); - total += VLAN_HLEN; copy = min_t(int, vlan_offset, len); ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);